1. Field of the Invention
The present invention relates to chip antennas, and more particularly, to a chip antenna used for mobile communications and used in local area network (LAN).
2. Description of the Related Art
As mobile communication units typical of which is a portable telephone have been made compact and lightweight, a chip antenna has been practically used as a compact antenna substitute for a large antenna such as a whip antenna or an inverted F antenna.
To mount a chip antenna on a unit stably and effectively, as shown in FIG. 7(a), a main body 51 is provided with a protruding section 52 at an end and a circuit board 54 on which a chip antenna 53 is mounted on the unit. The size of the unit, however, is increased by the protruding section.
To solve this problem, a rectangular circuit board 55 on which the chip antenna 53 is mounted in the vicinity of an end of the main body 51 may be used. See FIG. 7(b).
Since a conventional chip antenna is directly mounted on a circuit board of a unit as described above, a capacitance is generated between a conductor of the chip antenna and a ground electrode formed on the rear surface of the circuit board. With this capacitance, the gain of the chip antenna may decrease or the center frequency of the chip antenna may shift.